This invention relates to a driver for host bus adaptors connected to both a PCI bus and an I/O device unit of a computer system.
The I/O device unit such as the disk array device sold on the market in recent years realizes a high speed, a large capacity and a high reliability by combining a plurality of unit I/O devices.
In addition, in order to secure the redundancy between the system device and the I/O device unit, a plurality of host bus adaptors are mounted on the system device and connected with the I/O device unit through a plurality of paths, thereby securing a high reliability and a high speed of the interface as well as the redundancy.
The system configuration described above is very useful in that the system operation can be continued without suspension even in the case where the hardware develops a fault during the normal system operation.
At the time of installing an operating system (OS) in the system that has secured the redundancy, however, the user is required to cancel the redundant path connection and connect a single path and a single disk unit before carrying out the installation job. This is by reason of the fact that the installer for installing the operating system is not adapted for the system configuration having the redundant path connection, and therefore, at the time of installing the operating system, the order of disk recognition may be changed due to a fault, with the possible result that the data may be overwritten erroneously on other than a target disk unit.
In order to avoid this problem, the user is required to guarantee the connection of the single path and the single disk unit between the system device unit and the I/O device unit by changing the system configuration definition and inserting/removing the cable, before carrying out the job of installing the operating system.
The change of the system configuration definition and the cable insertion/removal requires the recheck of the connection path state after installation of the operating system, resulting in the consumption of a great amount of time.
JP-A-2005-251188 is available as a laid-open document related to this invention.